SEOUL — Younger South Koreans are increasingly second-guessing a national goal. They don’t think an eventual unification with North Korea will restore order and salve old wounds; they think it will turn a prosperous country into a chaotic one. More than half of those in their teens and 20s don’t even think unification is necessary — though they’re taught to believe as much starting in fifth grade.

For those who remember the Korean War and its aftermath, the Korean Peninsula’s split is untenable. “I will never accept it as a permanent condition,” President Lee Myung-bak, whose brother and sister were killed in the war, said last week in an address to the U.S. Congress.

But with more young South Koreans growing dubious about reunification, the government is trying to force an attitude adjustment. In recent weeks, it has launched an online-only sitcom and sponsored a network reality show with pro-unification themes.

If the message proves persuasive, South Korea can prevent a 60-year-old consensus from devolving into an argument. Unification, the government’s reasoning goes, would reunite families, stabilize the peninsula and — eventually — generate new economic potential in a country whose population would be 73 million instead of the current 49 million. Likelier, though, is that the taxpayer-funded campaign will do little to change minds, leaving the South with new questions about whether its quarrelsome neighbor should be viewed like any other foreign country, albeit one that shares the same language and poses a security threat.

Since a 1953 armistice agreement divided the peninsula and split thousands of families, South Korea has never treated the North like just another country. Even now, at a time when Pyongyang appears stable, the pro-unification stance serves as a guiding ideology for South Korean policymakers. Left-wingers and right-wingers have different strategies, but both want North Korea to drop its nuclear weapons program and open up its economy. In short, they want it to become more like the South as a starting point for a peaceful integration.

In Seoul, fewer young people believe that an eventual unification with the North is necessary. But the government makes a pro-unification stance part of its policy, with education beginning in fifth grade. (Chico Harlan/Washington Post)

In the 1990s, more than 80 percent of South Korea thought unification was essential, according to government polls. But that number has dropped to 56 percent. About 41 percent of those in their 20s feel that way. Among teens, the figure drops closer to 20 percent.

Young people see little to connect with in North Korea, with its authoritarian government and isolated economy. If the two economies were ever to join, the shock could derail the South’s rapid rise from poverty to prosperity, costing up to $1 trillion. Lee last year proposed a “unification tax” to help Seoul brace for the price of integration.

“Young people think the financial sacrifice will be huge,” Lee said in a recent interview. “That’s why they may have negative emotions toward unification.”

Seoul’s Unification Ministry, which handles North Korea policy, began a serious new-media push last year and ramped up those efforts this year. The ministry has always had a firm hand in the school curriculum, particularly at the elementary level. Fifth-graders, in their ethics class, receive a government-issued textbook titled “We Are One” that tells stories about North Korean life. “Sometime in the future,” the book says, North and South Koreans will live together.

A guide for high school teachers, issued by the Education Ministry, asks teachers to justify unification in a “systematic and rational way . . . so that students will have a more positive view.”

“From primary school on, we are drawing posters and making slogans and writing essays for unification,” said Yoon Jung-in, 24, a Seoul National University student who doesn’t think unification is necessary. “We do all this before we even form our own judgments. We sort of skip a step.”

With its $1.5 million new-media budget, the Unification Ministry this year has sponsored one television show and created another. The sponsored show, “Miracle Audition,” resembles an “American Idol” for actors, with a panel of judges scoring contestants. Sometimes, the contestants perform in car commercials (Hyundai is a sponsor); sometimes they laud the virtues of a skin cream (because of another sponsor). In a recent episode, one actor created a 30-second public service announcement for unification that depicted a clothesline, strung with photographs of ordinary Koreans, stretching across a horizon.

A government spokesman, Lee Jong-ju, said the public-relations push would promote the “dream and necessity” of unification. But some lawmakers have worried that portrayals of North Koreans could be too superficial or even derogatory. In one “Miracle Audition” challenge, contestants were asked to play spies.

But, mostly, the content is thought-provoking. In one episode of the online-only sitcom, a family that has adopted a North Korean defector debates what would happen to the South’s policy of mandatory military service if the country unifies with the North and the threat from the neighbor disappears.

Two of the actresses in the sitcom are in their 20s. One, Choi Yoon-seul, 28, said she had never thought much about North Korea before landing the role; she hadn’t needed to. But the other, Seol Joo-young, 24, had heard much about the North from her mother, who was born there.

“For the older generations, unification was a lifetime goal,” Seol said. “My generation, or even younger kids, they might think it’s an absurd thing to think about. But it’s kind of like a handed-down wish — something we can do for our ancestors.”